1. Field of the Invention
The present invention relates to a shock absorber for damping a shock applied to a quick return mirror or a camera body of a single lens reflex camera, when the quick return mirror is retracted from or moved into a photographing optical path.
2. Description of Related Art
In a single lens reflex camera, during the framing of a shot (viewing), a quick return mirror is normally located in the photographing optical path at an angle of approximately 45.degree. with respect to the optical axis of a photographing lens, to direct light transmitted through the photographing lens to a finder optical system (viewing position). Upon taking a picture, the quick return mirror is retracted from the photographing optical path to a picture taking position (operative position). After completion of the photographing operation, the quick return mirror is automatically returned to the viewing position.
To reduce the time in which a subject image disappears in the viewfinder, the quick return mirror must be moved as quickly as possible. However, shock generated when the quick return mirror stops increases as the speed of the quick return mirror increases. Consequently, the quick return mirror or the camera body can be damaged from the increased shock. To prevent this, it is known to provide a pneumatic shock absorber or damper in a drive mechanism for the quick return mirror. However, in conventional shock absorbers for single lens reflex cameras, it is impossible to adjust the ability to absorb the shock depending on the usage or purpose of the camera.